Yes, rooting for Mexico keeps the game lively and honors the global pattern of football, the universal function of sport.
Think of the World Cup as a grand experiment; when the USA exits, rooting for Mexico keeps the data flowing and the game's pattern honest. Curiosity loves the shared drama.
No. What you can control is your loyalty and conduct. Cheering Mexico betrays your duty and unsettles your Stoic calm; let the game be played, not fanned by your bias.